Normal Vibrations of Two Polymorphic forms of TeO₂ Crystals and Assignments of Raman Peaks of Pure TeO₂ Glass

Abstract

Raman spectra of paratellurite, tellurite and pure TeO₂ glass were measured. The normal vibration of paratellurite and tellurite was analyzed. The spectrum of pure TeO₂ glass were deconvoluted into symmetric Gaussian functions. The normal vibrations of paratellurite are exactly described as combined representations of movement of oxygen atom in Te-_eqO_ax-Te linkage and vibrations of TeO₄ trigonal bipyramid (tbp). Compared the resolved Raman peaks of pure TeO₂ glass with normal vibration of paratellurite, all Raman peaks from 420 to 880cm^-1 are assigned to the vibrations of TeO₄ tbp and Te-_eqO_ax-Te linkage. The antisymmetric stretching vibrations of Te-_eqO_ax-Te linkage have relatively large intensities to symmetric stretching vibrations of Te-_eqO_ax-Te linkage. In pure TeO₂ glass, TeO₄ tbps are formed by most of tellurium atoms and connected at vertices by the Te-_eqO_ax-Te linkages.